Answer:
2.5 m/s
Explanation:
The speed of the animal is given by the ratio between the distance travelled by the animal and the time elapsed:
where d is the distance travelled and t the time elapsed. Note that this quantity is also equal to the slope of the curve.
In the time interval 0-20 s, we have
d = 50 m - 0 m = 50 m
t = 20 s - 0 s = 20 s
So, the speed is
Answer:
Explanation:
<u>Given:</u>
- Mass,
- Velocity,
where,
are the uncertainties in mass and velocity respectively.
The kinetic energy is given by
The uncertainty in kinetic energy is given as:
Answer:
0.94 m/s^2 downwards
Explanation:
m = 70 kg, m g = 70 x 9.8 = 686 N
R = 620 N
Let the acceleration be a, as the apparent weight decreases so the elevator is moving downwards with an acceleration a.
mg - R = ma
686 - 620 = 70 x a
a = 0.94 m/s^2
Answer:
Definitely Spinning permanent magnets within an array of fixed permanent magnets
Explanation:
Any relative motion between magnets (be they permanent or electromagnetic) and a coil of wire will induce an electric current in the coil.
What will not induce an electric current is the relative motion between the two coils of wire (because there is no change in magnetic field), or the relative motion between two magnets (there are no coils of wire to induce the current into).
<em>Therefore, spinning permanent magnets within an array of fixed permanent magnets does not induce an electric current.</em>
